Fisher Gold Bug

[dbanner]

It would be nice to know the details of the RX coil and what resonance it is tuned at. Simply put, the scheme of the search head with internal components.
You should put the scope shots of the tx waveform with the RX waveform BEFORE the preamp side by side for comparison to see what's going on at null.(phase of RX coil residual voltage)
Hopefully you can return to project soon.

[ivconic]

Coil i have is original coil for Gold Bug 2, not for Gold Bug.
Today i realized that, by randomly finding totally stripped original pcb from Gold Bug 2.
Gold Bug works on 19kHz while Gold Bug 2 on 71kHz.
So actually i am having coil for 71kHz. All the time trying to make my diy work with it.
Now...
i gave up from further messing up with Lahr schematic as i posted earlier.
Noticed several errors.
But now i will in spite do the reverse engineering on pcb that i have.
It is stripped long time ago. No components on it. So this will be long term hobby joy.
Also discovered that this pcb is multilayer. 3 or 4 layers, not sure yet.
In spite all the odds, i proclaim "war on Gold Bug 2". It will be stripped down to ground zero and totally disclosed at the end.
In spite to it's arrogant designers and makers, who had funny pitiful delusion that are smart and that can stop this from reverse engineering.
This will be done. With or without any help from any random third party.
...
I just started:

[ivconic]

Yellow dots are -V layer and White dots are +V layer.
Next one update:

[ivconic]

KT315 you are collector of schematics and moreover photos.
Can you provide more details on Gold Bug 2, more photos, component list etc.
That would only shorten my job here.
If not; if there are no such photos, list etc ... than i will obtain original Gold Bug 2 and complete this job.
Sooner or later. It is just a matter of time.
But if i do all on my own; it will stay only for my eyes in my private archive.
People if you want me to share; you shall contribute too.
I seriously doubt that there are no people here having Gold Bug 2. No way!
Serious contribution would be taking photos on details and writing down component values.
For that job one should have no fears about his device. Nothing "aggressive" to do there.
Only to open enclosure and peek inside. Take photos and make a bill of material.
The rest is on me to do.
And that's the way to have here totally disclosed Gold Bug 2 and future diy with improvements and modifications.
Otherwise... if this forum remains dead horse as usual... i will do all on my own. But will not share it.
Simple as that.

[Qiaozhi]

Doesn't the Fisher Gold Bug 2 contain a microprocessor?
That will be a major obstacle to any back-engineering effort.

[hooby life]

You're right ivconic . Everyone here is concerned especially when there are fierce projects. And seize the opportunity as long as it is on the table.

[ivconic]

Doesn't the Fisher Gold Bug 2 contain a microprocessor?
That will be a major obstacle to any back-engineering effort.

Yes the "digital one" with COG display.
But before it there were Gold Bug and Gold Bug2 in the same enclosure but with different circuitry inside.
Lahr's hand drawn schematic that is present on forum is Gold Bug (1).

[ivconic]

You're right ivconic . Everyone here is concerned especially when there are fierce projects. And seize the opportunity as long as it is on the table.

I don't mind such people.
It's only that i remember the times where more (than one) people were ready to join and contribute the work.

[ivconic]

A little more updated.
So far identified chips:
MAX412
MC33178
TLV2262
CMP01CP
LM394
TLC372CP
27M9
74HC4053
4053
LM358
LP2951CN
...
CMP01CP is interesting one.

[gurdal]

hi all
I don't know much about circuit design.
Believe me, I would like to join you and support you.
unfortunately, I cannot go beyond copying.
If anything I can do I'm ready to help.
Yours truly
Gurdal

[ivconic]

hi all
I don't know much about circuit design.
Believe me, I would like to join you and support you.
unfortunately, I cannot go beyond copying.
If anything I can do I'm ready to help.
Yours truly
Gurdal

Only if you have chance to peek inside Gold Bug 2.
Take detailed photos and list the component values.
That not need any desoldering or any other kind of disturbing or risking the circuitry.

[Qiaozhi]

There's one here for sale in the U.S. ->
https://www.ebay.com/itm/193714872347

Cheapest I've seen.

[kt315]

Doesn't the Fisher Gold Bug 2 contain a microprocessor?
That will be a major obstacle to any back-engineering effort.

modern Fisher GB2, of First Texas, has.

[kt315]

KT315 you are collector of schematics and moreover photos.
Can you provide more details on Gold Bug 2, more photos, component list etc.
---
if people do not wish to share pics i get too nothing. just some guys give HR pics.
sorry, have nothing on GB2. just this sch of W. Lahr all have. also there was a sketch of coil.
thats all.

[dbanner]

Deja- Vu?
https://www.geotech1.com/forums/show...light=Gold+bug

You are man of great courage my friend, that thing looks scary.